Web handling apparatus

ABSTRACT

Apparatus for handling a running web including oppositely disposed air bars for drying and/or positioning the web as it passes between the air bars. Means are provided for quickly and easily inserting and removing the air bars for replacement or maintenance and also for insuring that the air bars are located precisely with respect to one another and with respect to the web. An elongated air bar for web handling apparatus and having an air receiving hole intermiediate its length and also having bracket means extending from its ends for quick attachment to the apparatus. The air bar also has guide means for guiding the hole in the bar into precise registry with an air supply hole of an air supply duct.

I Umted States Patent 1 [111 3,776,440

Frost et al. 51 Dec. 4, 1973 WEB HANDLING APPARATUS Primary Examiner-Richard A. Schaeher 751 Inventors: John w. Frost; Paul H. Stibbe, both Nllles of De Pere, Wis.

[73] Assignee: TEC Systems, Inc., De Pere, Wis. [57] ABSTRACT [22] Filed: 1 0, 1973 Apparatus for handling a running web including oppo- 21 A L N J 327 995 sitely disposed air bars for drying and/or positioning 1 pp 0 the web as it passes between the air bars. Means are provided for quickly and easily inserting and removing [52] US. Cl. 226/97, 34/156 th air bar for replacement or maintenance and also [5 1] Int. Cl B65]! 17/32 for insuring that the air bars are located precisely with [58] Field Of Search 226/7, 97; 34/ 156 respect to one another and with respect to the web.

An elongated air bar for web handling apparatus and [56] References C'ted having an air receiving hole intermiediate its length UNITED STATES PATENTS and also having bracket means extending from its ends 3,448,907 6/1969 Otepka 226/97 for quick attachment to the apparatus. The air bar 3,537,177 6/1971 O er y 34/156 also has guide means for guiding the hole in the bar 3,680,218- 8/1972 Belue 34/156 X into precise registry with an air supply hole of an air supply duct.

22 Claims, 9 Drawing Figures WEB HANDLING APPARATUS BACKGROUND OF THE INVENTION The invention pertains generally to web drying and- /or web positioning and includes air nozzles for drying and/or floating the web between the nozzles so that the web does not touch the apparatus, but instead is suspended by air. The spacing of the oppositely disposed nozzles from one another and also from the web is particularly important so as to properly dry the web as it passes between the nozzles and in addition, properly float the web without fluttering and without touching parts of the apparatus. These air bars must be periodically removed and their air nozzles cleaned and this has been a troublesome task because of the limited space in the apparatus for access to the air bars and the fastening means. Web handling apparatus of the general type is very often quite sizeable and extends for considerable lengths. One side of such apparatus is usually referred to as the operators side and the controls and adjustments are frequently located on the operators side. The opposite side is usually more remote and unaccessible and it is difficult to gain access to the air bars at that side of the apparatus.

Apparatus of this general type is shown in the US. Pat. application Ser. No. 182,639, filed Sept. 22, 1971 and entitled High Velocity Air Web Dryer, which application issued as US. Pat. No. 3,739,491 on June 19, 1973. That apparatus shows a dryer having an upper air bar assembly and a lower air bar assembly, the latter of which is retracted in a planer or straight line movement down away from the upper assembly to thereby gain access to the nozzles. The present invention however, is applicable to either of the said planer type retraction or a pivotal type of retraction for the lower air bar assembly which will be described in this present application.

The air bars of the present application may be of the general type as shown in the US. Pat. No. 3,549,070, which issued Dec. 22, 1970 and entitled Floatation of Sheet Materials and reference may be had to that pa tent if deemed necessary or desirable as far as understanding the general principle of the air bar itself.

SUMMARY OF THE PRESENT INVENTION The present invention provides web handling apparatus having air bars for drying and/or floatingly positioning the moving web, and which air bars can be inserted or withdrawn from the apparatus in a generally endwise direction of the air bar and from one side only of. the apparatus. The means for so mounting and positioning the air bars permits the inner end of the air bar, that is the end of the air bar remote from the operator's side to be slipped into place in an endwise manner at the remote side of the apparatus, and then the other end of the air bar is moved into its proper position at the oper ator or rear side of the apparatus. As the air bar is thus movedinto its final position, guide means are provided for accurately positioning the air bar in a longitudinal direction, that is in a direction in which the web extends. The mounting means so provided for the air bars insures that the air bars are not only positioned in parallelism with one another and at properly spaced distances from one another, but also insures that the face of the air bar adjacent the web is located precisely with the web and also with respect to the opposed air bar at the other side of the web. With the present invention, the air bar is precisely located in all directions with re spect to other air bars and with respect to the web and such positioning can be accomplished in a relatively easy manner from the operators side of the apparatus. The air bars are inserted in a fool-proof manner by inexperienced operators with a minimum amount of time and effort. Furthermore, the mounting of the air bars is such that the air bar is free to expand and this is important due to the wide range of temperatures to which the air bars are subjected.

These and other objects and advantages of the present invention will appear hereinafter as this disclosure progresses, reference being bad to the accompanyin drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a transverse, elevational view, in section, taken through a web handling apparatus embodying the present invention, certain parts being shown as broken away or removed for the sake of clarity and the view showing the opposed air bars in operating position;

FIG. 2 is a view similar to FIG. 1,- but showing the lower air bar assembly when pivoted to a non-operative position wherein oneof the lower air bars is shown as being removed from the assembly as when for example it is to be removed from or replaced on the assembly;

FIG. 3 is a perspective, end view of a portion of the lower air bar assembly and then showing several of the air bars removed, certain parts being shown as broken away or removed for the sake of clarity;

FIG. 4 is a perspective view of one of the air bars when removed from the assembly and laid on its side so as to see the construction of the underside of the air bar and the guide means inserted thereon;

FIG. 5 is a view generally similar to FIG. 3, but showing an air bar in the disassembled position or that is to say when it is being removed from or inserted on the air supply ducts and support frame structure;

FIG. 6 is an enlarged, partially cross sectional view through one of the air bars and the portion of the duct to which it is attached, the view being taken generally along the line 6-6 in FIG. 2;

FIG. 7 is a view similar to FIG. 6, but showing the air bar in position on the air supply duct;

FIG. 8 is an enlarged, fragmentary view of a portion of the device shown in' FIG. 6, certain parts being removed or broken away for the sake of clarity; and

FIG. 9 is a perspective view of the guide means shown in FIGS. 6 and 7 which are inserted in the air receiving holes of the air bar.

DESCRIPTION OF A PREFERRED EMBODIMENT The apparatus provided by the present invention includes an upper air bar assembly UA and a lower air bar assembly LA, between which a web W is dried and- /or floated. The assemblies may be movable relative to one another to'a certain extent, and as shown in the present modification, the upper assembly is fixed within the apparatus while the lower assembly can be pivoted about the point 1, as shown in FIG. 2 so that its remote or operators end 2 can be lowered from the upper assembly so as to gain access to the air bars 3 and 4 removably fixed to the upper and lower assemblies.

. The invention also finds utility in other types of retraction devices for the air bar assemblies and generally speaking, the inner side IS of the apparatus is usually restricted as to its access, while the operators side OS contains the access doors, adjustments, and is available to the mechanics and operators from the floor of the plant.

As the general construction of the lower assembly is similar to the upper assembly, reference will be made herein to the lower assembly for convenience in describing the invention, it being understood that the construction of the upper assembly, including the air bars, supply ducts, etc., are similar to that of the lower assembly.

The lower assembly is shown clearly in FIGS. 3 and 5 and includes a support frame F having two transversely spaced apart and longitudinally extending side members and 11. It will be understood that for the sake of convenience in describing the invention, the term longitudinally" means the direction in which the web moves through the apparatus. These side members are fabricated from steel, commonly referred to as angle iron members, and are precisely located in the frame so as to cooperate with the air bars to be described. Air supply ducts 13 and 14 extend longitudinally in the apparatus and are located between the side members 10 and 11 and are rigidly secured in the frame F. Various numbers of these ducts may be used, including a singular, but perhaps wider, duct located between the members 10 and 11. In any event, these ducts receive air from a cross header 15 (FIG. 2) from an air supply source such as a fan (not shown). Thus air under pressure is supplied to the ducts and the ducts have a series of holes 17 extending through their transverse sides 18. The holes 17 are defined by an upwardly turned flange 20 which is pressed or formed in the transverse side 18. It will be understood that the term upwardly is used in connection with the lower ducts l3 and 14, for convenience only in describing the apparatus. Thus the holes are air supply holes through which the pressurized air is forced into the air bars now to be described.

The air bars AB are elongated and generally tubular in construction and shown here as being generally rectangular in cross section. These air bars each have an air nozzle extending longitudinally along each of its sides and also having a series of perforations'31 spaced along their length and in their flat plate surface 32. As is conventional practice, the web W is supported between the opposed air bars AB of the upper assembly US and the lower assembly LA. The location of the surfaces 32 of the opposed air bars relative to one another is important and furthermore, it is important that the air bars of either assembly are in parallelism with one another. The air bars on their inner sides, that is on the side adjacent the supply ducts have holes 34 which are adapted to register with the supply holes 17 of the air ducts. The holes 34 of the air bars are defined as shown clearly in FIGS. 6, 7 and 8 by an outwardly turned flange 36. An annular flange member 37 is welded as at 38 and defines with flange 36 a pocket 39 in which gasket material 40 is located. The gasket material 40 is flexible or compressible to a certain extent and as shown in FIG. 7 is adapted to abut against the flange 20 of the duct when the air bar is assembled on the duct. It will be noted that the annular flange 36 of the air bar is adapted to nest generally within the annular flange 20 of the duct. Thus when the air bar is assemblied on the ducts, the aligned holes between the air bars and ducts are sealed and pressurized air enters into the duct and the air bar for discharge through the air bar nozzles against the web.

The air bars are fastened to the supply ducts as follows. One bracket means is secured to the inner end of the air bar, that is at the end of the air bar which is usually remote from the operators side of the apparatus. This bracket means comprises an angle shaped steel bracket 42 which has one of its legs 43 welded to the outside of the end of the air bar. The other leg 44 has a hole 45 and extends from the air bar and is adapted to be slipped underneath the frame member 11. A second bracket means 52 is provided at the other end of the air bar and is also fashioned as a right angle steel member having one of its flanges 53 welded to the end of the air bar while its other flange 54 extends outwardly and endwise from the air bar. The flange 54 has a hole 55 drilled therethrough for the passage of a bolt 56. Holes 45 and 55 are somewhat larger than the bolt 56 for a purpose that will hereinafter appear. The frame member 10 has a series of holes 57 therein which are tapped to threadingly receive the bolts 56. These tapped holes 57 are located precisely along the frame member 10.

The bracket means 42 and bracket means 52 at opposite ends of the air bar are similar to one another and are also located similarly on the air bar as shown in FIGS. 1 and 2. It will be noted however, that the frame member 11 is a slightly different elevation that the opposite frame member 10 so that when the one bracket 42 is slipped under the frame member 11 and the other bracket 52 is placed on top or on the outer surface of the frame member 10, the opposite air bars 3 and 4 are parallel to one another and are horizontally disposed.

The length of the air bars are usually such that they overhang or extend beyond the web W by about 1 inch at each end. It is therefore possible to make the holes 55 in the second bracket means slightly larger than the bolt 56 which extends therethrough. This construction together with the fact that the other bracket means simply slides under the frame member 11, permits accurate positioning of the air bar in its endwise direction with respect to the duct, but at the same time permits thermal expansion of the air bars relative to the frame and due to the wide temperature ranges to which they are subjected. Thus, the air bars are installed in their endwise direction, that is from one side of the apparatus simply by slipping the one bracket means under the frame member and then lowering or moving the other end of the air bar against the other frame member 10 where the second bracket means rests thereon and is removably secured thereto by the bolt means. The position of the alignable flanges of the duct and the air bars are such that as the air bar is swung toward the ducts, the flanges of the duct engage the sealing means 40 and compress it slightly when the second bracket means of the air bar is finally positioned against the frame member. Thus, the bracket means and their position relative to the frame members accurately positions the sealing means between the air bars and ducts.

Means are also provided for guiding the air bar and more specifically, the holes 34 of the air bars into longitudinal alignment with the holes 17 of the air ducts. That is to say, means are provided for positioning the air bars in a direction of web movement with respect to the air ducts so that proper registry therebetween is assured. This means is shown in FIGS. 4, 6-9 and comprises a steel plate-like member 60 having an inner portion 61 which is press-fit into the outwardly turned flange 36 of the air bar so as to be firmly held therein.

This guide means 60 extends across the air bar and also extends therefrom and has oppositely inclined or angled guide surfaces 63 and 64 which are guidingly received-in the outwardly turned'flange 20 of'theduct. The maximum length of the guide means is defined by its outer surface 66 and 67,which, when the air bar is assembled on the duct, fit against the inner surface of the outwardly extending flange 20; When in the assembled position as shown-in FIG. 7, the air bars are precisely located in a longitudinal direction, and relative to one another and insures parallelism between the air bars. Thus with the present guide means, the operator is aided in precisely locating the air bars in a longitudinal direction which has heretofore been difficult because of the inaccessibility due to space limitations and also due to lack of ability to visually observe the parts within the machine during the installing operation.

To replace or remove the air bars it is only necessary to remove or replace the bolt means 56 and installation and removal of the air bar itself is done with a simple endwise movement of the air bar. The inner or remote end of the air bar and more specifically, the one bracket means is slipped endwise of the frame member with abutment with the member and this slipping or endwise movement is with the air bar at the angle as shown'in FIGS. 2 or 5. The air bar can then be'pivoted more or less generally about the one bracket means into engagement with the duct means for removal therefrom. The holes between the air bar and duct means are accurately and precisely guided into alignment and the seal means is compressed to the proper degree for insuring that the air bars are accurately and firmly held in proper air communication with the duct.

In addition to ease of removal of air bars for maintenance, cleaning or repairing, the present invention prevents installation of the air bars in an improper manner due to the similarlity between the bracket means at opposite ends of the air bar and which permit installation of the air bar in either end for end position, and in either case, the air bar is accurately and firmly positioed relative to the duct.

We claim:

air bar is constructed and arranged to abut against a side of said other member which is opposite to said one side of said one member, whereby abutment of said second bracket means with said other member acts to bring said air bar down firmly on said supply duct.

3. The apparatus as set forth in claim 1 further characterized in that said hole in said supply duct is defined by an upwardly turned flange therearound, and said seal means abuts against said upwardly turned flange, and said air bar hole is defined by a projecting annular flange which abuts against said seal means.

4. The apparatus as set forth in claim l including a guide means extending across said air bar hole and which guide means is of such size and shape so as to be guidingly received in the air hole of said duct, whereby said air bar hole is guided into longitudinal alignment with said duct hole as said second bracket means is moved into engagement with said other member.

5. The apparatus as set forth in claim 4 further characterized in that said guide means has tapered sides for being guidingly inserted in said duct air hole.

6. Apparatus as set forth in claim 1 further characterized in that said detachable means comprises alignable bolt holes in said second bracket means and said other member, and also including bolt means for engagement in said bolt holes, whereby said detachable means acts to align said air bar on said duct in a transverse direction for proper registry of the air holes therebetween.

7; Web handling apparatus comprising; two transversely spaced apart members, an air supply duct having a transverse side located between said two members, said transverse side having a supply air hole therein for supplying air to an air bar attached thereto and in air receiving communication therewith,an elongated air bar having a receiving air hole which registers with said air hole in said transverse side, seal means between said aligned holes for establishing an air seal therebetween, said air bar having one bracket means at one end for engagement under one of said members, said air bar also having second bracket means at its other end for engagement on the other of said members, guide means extending across said air bar hole 1. Web handling apparatus comprising; two transversely spaced apart members and an air supply duct having a transverse side located between said two members, said transverse side having a supply air hole therein for supplying air to an air bar attached thereto and in air receiving communication therewith, an elongated air bar having a receiving air hole which registers with said air hole'in said transverse side, seal means between said aligned holes for establishing an air seal therebetween, said air bar having one bracket means at one end for engagement under one of said members, said air bar also having second bracket means at its other end for engagement on the other of said members, and detachable means for engagement with and between said second bracket means and said other member for releasably securing said other end of said air bar to said other member, whereby said seal means is brought into sealing engagement between said aligned holes and said air bar is accurately and firmly held in air receiving communication with said duct.

2. The apparatus as defined in claim 1 further characterized in that said one bracket means at one end of said airv bar is constructed and arranged to he slipped under and abut against one side of said one member, and the second bracket means at the other end of said whereby said air bar hole is guided into longitudinal alignment with said duct hole as said second bracket means of said air bar is moved into abutment on said other member; and detachable means for engagement with and betweensaid second bracket means and said other member, said detachable means including alignable bolt holes in said second bracket means and said other member, and also including bolt means for engagement in said bolt holes, whereby said detachable means acts to align said air bar endwise on said duct for proper registry of the air holes therebetween, whereby when said one bracket means has been engaged under said one member and said second bracket means is then moved into abutment with said other member, said seal means is brought into sealing engagement between said aligned holes and said air bar is accurately and firmly held in air receiving communication with said duct.

8. The apparatus as set forth in claim 7 further characterized in that'said hole in said supply duct is defined by an upwardly turned flange therearound, and said air bar hole is defined by a projecting annular flange which registers with said duct flange.

9. The apparatus as set forth in claim 7 further characterized inthat said guide means has tapered sides for being guidingly inserted in said hole of said duct means.

10. Web handling apparatus comprising; a support frame having two transversely spaced apart longitudinally extending side members, an air supply duct rigidly mounted in said frame and having a transverse side between said members, said transverse side having an air hole therein for supplying air to an air bar, an elongated air bar detachably secured to said duct means and having an air hole which registers with said air hole in said transverse side, gasket means between said aligned air holes for establishing an air sea] therebetween, said air bar having one bracket means extending from one end and for endwise insertion under one of said members for abutment thereagainst, said air bar also having a second bracket means extending from its other end for abutment on the other of said members, and removable bolt means extending through said second bracket means and said other member for releasably securing said other end of said air bar to said other member, whereby when said one bracket means is inserted endwise under said one member, the other end of said air bar can be swung about said one end as a pivot and into abutment with said other member and in so doing said gasket means is compressed in sealing engagement between said aligned holes and consequently said air bar is accurately and firmly held in air receiving communication with said duct means but can be removed endwise therefrom when said bolt means is removed.

1 l. The apparatus as defined in claim 10 further characterized in that said one bracket means at one end of said air bar is so constructed and arranged to be inserted under and abut against one side of said one member, and the second bracket means at the other end of said air bar is constructed and arranged to abut against a side of said other member which is opposite to said one side of said one member, whereby abutment of said second bracket means with said other member acts to force said air bar down firmly on said supply duct.

12. The apparatus as set forth in claim 10 further characterized in that said supply duct hole is defined by an upwardly turned flange, and said air bar hole is defined by a projecting annular flange which registers with said duct flange.

13. The apparatus as set forth in claim 10 including a guide means extending across said air bar hole whereby said air bar hole is guided into longitudinal alignment with said duct hole as said other end of said air bar is moved into abutment with said other member.

14. The apparatus as set forth in claim 13 further characterized in that said guide means has tapered sides for being guidingly inserted in said duct hole.

15. Apparatus as set forth in claim 10 further characterized in that said detachable means comprises alignable bolt holes in said second bracket means and said other member, and also including bolt means for engagement in said bolt holes, whereby said detachable means acts to align said air bar on said duct in a transverse direction for proper registry of the air holes therebetween.

16. Web handling apparatus comprising; air supply duct means having two transversely spaced apart members, an air supply duct having a transverse side located between said members, said transverse side having a hole therein for supplying air to an air bar attached thereto and in air receiving communication therewith, an elongated air bar having a hole which registers with said hole in said transverse side, gasket means between said aligned holes for establishing an air seal therebetween, said air bar having one bracket means at one end for engagement under one of said members by being slipped endwise thereunder, said air bar also having a second bracket means at its other end for engagement on the other of said members, and detachable means for engagement with and between said second bracket means and said other member for releasably securing said other end of said air bar to said other member, whereby when said one bracket means is slipped under said one member, the other end of said air bar can be swung about said one end as a pivot and into engagement with said other member and in so doing said gasket means is compressed in sealing engagement between said aligned holes and consequently said air bar is accurately and firmly held in air receiving communication with said duct means.

17. Web handling apparatus comprising; two transversely spaced apart members and an air supply duct having a transverse side located between said two members, said transverse side having a supply air hole therein for supplying air to an air bar attached thereto and in air receiving communication therewith, said supply air hole being defined by an outwardly turned flange therearound, an elongated air bar having a receiving air hole defined by a projecting annular flange which registers with said air hole in said transverse side, seal means between said flanges of said aligned holes for establishing an air seal therebetween, said air bar having one bracket means at one end and constructed and arranged to be slipped under and abut against one side of said one member, said air bar also having second bracket means at its other end and constructed and arranged to abut against a side of said other member which is opposite to said one side of said one member for engagement with and between said second bracket means and said other member for releasably securing said other end of said air bar to said other member, whereby abutment of said second bracket means with said other member acts to bring said air bar down firmly on said supply duct, and guide means extending across said air bar hole and which guide means is of such size and shape so as to be guidingly received in the air hole of said duct, whereby said air bar hole is guided into longitudinal alignment with said duct hole as said second bracket means is moved into engagement with said other member, said seal means is brought into sealing engagement between said aligned holes and said air bar is accurately and firmly held in air receiving communication with said duct.

18. Apparatus as set forth in claim 17 further characterized in that said detachable means comprises alignable bolt holes in said second bracket means and said other member, and also including bolt means for engagement in said bolt holes, whereby said detachable means acts to align said air bar on said duct in a transverse direction for proper registry of the air holes therebetween.

19. An elongated air bar for web handling apparatus of the type having two transversely spaced apart members and an air supply duct having a transverse side including an air hole and located between said two members, said air bar having a receiving air hole intermediate its length, said air bar also having one bracket means at one end for engagement under one of said members, and said air bar also having second bracket 9 10 means at its other end for engagement on the other of characterized in that said guide means has tapered Said members' sides for being guidingly inserted in said duct air hole.

20. The apparatus as set forth in claim 19 including a guide means extending across said air bar hole and which guide means is of such size and shape so as to be 5 guidingly received in the air hole of said duct. by an outwardly turned flange therearound- 21. The apparatus as set forth in claim 20 further 22. The apparatus as set forth in claim 19 further characterized in that said hole in said air bar is defined 

1. Web handling apparatus comprising; two transversely spaced apart members and an air supply duct having a transverse side located between said two members, said transverse side having a supply air hole therein for supplying air to an air bar attached thereto and in air receiving communication therewith, an elongated air bar having a receiving air hole which registers with said air hole in said transverse side, seal means between said aligned holes for establishing an air seal therebetween, said air bar having one bracket means at one end for engagement under one of said members, said air bar also having second bracket means at its other end for engagement on the other of said members, and detachable means for engagement with and between said second bracket means and said other member for releasably securing said other end of said air bar to said other member, whereby said seal means is brought into sealing engagement between said aligned holes and said air bar is accurately and firmly held in air receiving communication with said duct.
 2. The apparatus as defined in claim 1 further characterized in that said one bracket means at one end of said air bar is constructed and arranged to be slipped under and abut against one side of said one member, and the second bracket means at the other end of said air bar is constructed and arranged to abut against a side of said other member which is opposite to said one side of said one member, whereby abutment of said second bracket means with said other member acts to bring said air bar down firmly on said supply duct.
 3. The apparatus as set forth in claim 1 further characterized in that said hole in said supply duct is defined by an upwardly turned flange therearound, and said seal means abuts against said upwardly turned flange, and said air bar hole is defined by a projecting annular flange which abuts against said seal means.
 4. The apparatus as set forth in claim 1 including a guide means extending across said air bar hole and which guide means is of such size and shape so as to be guidingly received in the air hole of said duct, whereby said air bar hole is guided into longitudinal alignment with said duct hole as said second bracket means is moved into engagement with said other member.
 5. The apparatus as set forth in claim 4 further characterized in that said guide means has tapered sides for being guidingly inserted in said duct air hole.
 6. Apparatus as set forth in claim 1 further characterized in that said detachable means comprises alignable bolt holes in said second bracket means And said other member, and also including bolt means for engagement in said bolt holes, whereby said detachable means acts to align said air bar on said duct in a transverse direction for proper registry of the air holes therebetween.
 7. Web handling apparatus comprising; two transversely spaced apart members, an air supply duct having a transverse side located between said two members, said transverse side having a supply air hole therein for supplying air to an air bar attached thereto and in air receiving communication therewith, an elongated air bar having a receiving air hole which registers with said air hole in said transverse side, seal means between said aligned holes for establishing an air seal therebetween, said air bar having one bracket means at one end for engagement under one of said members, said air bar also having second bracket means at its other end for engagement on the other of said members, guide means extending across said air bar hole whereby said air bar hole is guided into longitudinal alignment with said duct hole as said second bracket means of said air bar is moved into abutment on said other member; and detachable means for engagement with and between said second bracket means and said other member, said detachable means including alignable bolt holes in said second bracket means and said other member, and also including bolt means for engagement in said bolt holes, whereby said detachable means acts to align said air bar endwise on said duct for proper registry of the air holes therebetween, whereby when said one bracket means has been engaged under said one member and said second bracket means is then moved into abutment with said other member, said seal means is brought into sealing engagement between said aligned holes and said air bar is accurately and firmly held in air receiving communication with said duct.
 8. The apparatus as set forth in claim 7 further characterized in that said hole in said supply duct is defined by an upwardly turned flange therearound, and said air bar hole is defined by a projecting annular flange which registers with said duct flange.
 9. The apparatus as set forth in claim 7 further characterized in that said guide means has tapered sides for being guidingly inserted in said hole of said duct means.
 10. Web handling apparatus comprising; a support frame having two transversely spaced apart longitudinally extending side members, an air supply duct rigidly mounted in said frame and having a transverse side between said members, said transverse side having an air hole therein for supplying air to an air bar, an elongated air bar detachably secured to said duct means and having an air hole which registers with said air hole in said transverse side, gasket means between said aligned air holes for establishing an air seal therebetween, said air bar having one bracket means extending from one end and for endwise insertion under one of said members for abutment thereagainst, said air bar also having a second bracket means extending from its other end for abutment on the other of said members, and removable bolt means extending through said second bracket means and said other member for releasably securing said other end of said air bar to said other member, whereby when said one bracket means is inserted endwise under said one member, the other end of said air bar can be swung about said one end as a pivot and into abutment with said other member and in so doing said gasket means is compressed in sealing engagement between said aligned holes and consequently said air bar is accurately and firmly held in air receiving communication with said duct means but can be removed endwise therefrom when said bolt means is removed.
 11. The apparatus as defined in claim 10 further characterized in that said one bracket means at one end of said air bar is so constructed and arranged to be inserted under and abut against one side of said one member, and the second bracket means at the other end of said air bar is constructed and arranged to abut against a side of said other member which is opposite to said one side of said one member, whereby abutment of said second bracket means with said other member acts to force said air bar down firmly on said supply duct.
 12. The apparatus as set forth in claim 10 further characterized in that said supply duct hole is defined by an upwardly turned flange, and said air bar hole is defined by a projecting annular flange which registers with said duct flange.
 13. The apparatus as set forth in claim 10 including a guide means extending across said air bar hole whereby said air bar hole is guided into longitudinal alignment with said duct hole as said other end of said air bar is moved into abutment with said other member.
 14. The apparatus as set forth in claim 13 further characterized in that said guide means has tapered sides for being guidingly inserted in said duct hole.
 15. Apparatus as set forth in claim 10 further characterized in that said detachable means comprises alignable bolt holes in said second bracket means and said other member, and also including bolt means for engagement in said bolt holes, whereby said detachable means acts to align said air bar on said duct in a transverse direction for proper registry of the air holes therebetween.
 16. Web handling apparatus comprising; air supply duct means having two transversely spaced apart members, an air supply duct having a transverse side located between said members, said transverse side having a hole therein for supplying air to an air bar attached thereto and in air receiving communication therewith, an elongated air bar having a hole which registers with said hole in said transverse side, gasket means between said aligned holes for establishing an air seal therebetween, said air bar having one bracket means at one end for engagement under one of said members by being slipped endwise thereunder, said air bar also having a second bracket means at its other end for engagement on the other of said members, and detachable means for engagement with and between said second bracket means and said other member for releasably securing said other end of said air bar to said other member, whereby when said one bracket means is slipped under said one member, the other end of said air bar can be swung about said one end as a pivot and into engagement with said other member and in so doing said gasket means is compressed in sealing engagement between said aligned holes and consequently said air bar is accurately and firmly held in air receiving communication with said duct means.
 17. Web handling apparatus comprising; two transversely spaced apart members and an air supply duct having a transverse side located between said two members, said transverse side having a supply air hole therein for supplying air to an air bar attached thereto and in air receiving communication therewith, said supply air hole being defined by an outwardly turned flange therearound, an elongated air bar having a receiving air hole defined by a projecting annular flange which registers with said air hole in said transverse side, seal means between said flanges of said aligned holes for establishing an air seal therebetween, said air bar having one bracket means at one end and constructed and arranged to be slipped under and abut against one side of said one member, said air bar also having second bracket means at its other end and constructed and arranged to abut against a side of said other member which is opposite to said one side of said one member for engagement with and between said second bracket means and said other member for releasably securing said other end of said air bar to said other member, whereby abutment of said second bracket means with said other member acts to bring said air bar down firmly on said supply duct, and guide means extending across said air bar hole and which guide means is of such size and shape so as to be guidingly received in the air hole of said duct, whereby said air bar hole Is guided into longitudinal alignment with said duct hole as said second bracket means is moved into engagement with said other member, said seal means is brought into sealing engagement between said aligned holes and said air bar is accurately and firmly held in air receiving communication with said duct.
 18. Apparatus as set forth in claim 17 further characterized in that said detachable means comprises alignable bolt holes in said second bracket means and said other member, and also including bolt means for engagement in said bolt holes, whereby said detachable means acts to align said air bar on said duct in a transverse direction for proper registry of the air holes therebetween.
 19. An elongated air bar for web handling apparatus of the type having two transversely spaced apart members and an air supply duct having a transverse side including an air hole and located between said two members, said air bar having a receiving air hole intermediate its length, said air bar also having one bracket means at one end for engagement under one of said members, and said air bar also having second bracket means at its other end for engagement on the other of said members.
 20. The apparatus as set forth in claim 19 including a guide means extending across said air bar hole and which guide means is of such size and shape so as to be guidingly received in the air hole of said duct.
 21. The apparatus as set forth in claim 20 further characterized in that said guide means has tapered sides for being guidingly inserted in said duct air hole.
 22. The apparatus as set forth in claim 19 further characterized in that said hole in said air bar is defined by an outwardly turned flange therearound. 